反应详情

3,4,5,6-Tetrabromopyridine-2-carboxamide (5.0 g) was selectively aminated with ammonia gas at RT in 100 mL methanol. The resultant solution was concentrated to an off-white solid and hydrolyzed with conc. sulfuric acid (25 mL) at 140° C. for 3 hr. the mixture was made basic with NaOH, extracted with EtOAc (2×100 mL), acidified and filtered to give 1.4 g of pure 4-amino-3,6-dibromopyridine-2-carboxylic acid; mp 205° C. dec.

1. concentrationThe resultant solution was concentrated to an off-white solid and hydrolyzed with conc. sulfuric acid (25 mL) at 140° C. for 3 hr
2. extractionextracted with EtOAc (2×100 mL)
3. filtrationfiltered